A plug-in electric vehicle may require electricity in between vehicle uses or operation in order to charge its rechargeable battery pack. In most applications, a battery charger receives power from an external power source such as a 110V or 220V AC power outlet, and then rectifies and/or transforms the power to a form and level that is suitable for charging the rechargeable battery pack that resides on the plug-in electric vehicle.
During the charging process, other vehicle systems—like a vehicle heating, ventilation and air conditioning (HVAC) system—may also request electrical power from the external power source. In some instances, the amount of power requested exceeds the amount of power available; put differently, the external power source may not have enough power to satisfy all of the requests that are being made by the different vehicle systems, including charging the rechargeable battery pack.